<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        html,body{
            width: 100%;
            height: 100%;
            padding: 0;
            margin: 0;
            overflow: hidden;
        }
    </style>
</head>
<body>
    <h1 style="margin-left: 35%;color: #373d41;font-size: 60px;">点击右上角选择功能</h1>
</body>
</html>